Self-propelled sheet metal shear



May 17, 1955 c. F. ENGEL v2,708,480

SELF-PROPELLED SHEET METAL SHEAR Filed Nov. 2, 1953 :4 2 I] Y2 23 7 I?ma F F|G.6 18

I INVENTOR. 57 11 CHARLES FRANK ENGEL 35 52 M, ATTORNEY United StatesPatent SELF-PROPELLED SHEET METAL SHEAR Charles F. Engel, Sparta, Ill.

Application November 2, 1953, Serial No. 389,624

11 Claims. (Cl. 164-76) This invention relates to sheet metal shears,and particularly to shears having disc cutters for cutting rectilinearsheet edges, as for duct work and the like.

Rolling shears have been used from time to time with sheet metal worktables equipped with sheet-holding clamps, for the purpose of cuttinglong, straight or tapering sheet metal pieces. With light weight sheetmetal, as is used for ducts, a difiiculty frequently encountered is thebuckling of the sheet during the cutting operation. With heavier weightsheet metal, despite the use of clamps, rolling shears have shown atendency to draw the sheet metal off or move it farther onto the worktable; and with light weight sheets, to cause buckling. Theseundesirable effects have been multiplied when attempts were made toapply power to the shears.

A principal purpose of the present invention is to overcome theseproblems and provide a power-operated shear for cutting sheet metalaccurately and without deviating from an intended rectilinear.

A further purpose is to provide a self-propelled shear for sheet metalwhich will overcome the tendency toward moving the sheet metal onto oroff of the work table.

A still further purpose is to provide a rolling shear having adjustablemechanism whereby this sheet-moving tendency may be overcome for sheetsof metal of different thicknesses and tempers.

In the accompanying drawings:

Figure 1 is an outer side elevation of a removable shear embodying thepresent invention, shown without the carriage therefor;

Figure 2 is a plan view of the removable shear shown in Figure 1;

Figure 3 is an inner side elevation of the carriage for the shear ofFigure 1;

Figure 4 is an aft end view of the carriage of Figure 3, shown mountedon a track secured to the side of a work table;

Figure 5 is an inner side elevation of the assembled shear, shownwithout a track;

Figure 6 is an aft end view of the assembled shear of Figure 5;

Figure 7 is a sectional view taken along line 7-7 of Figure 5; and

Figure 8 is a sectional view similar to Figure 7, but showing alternateresilient alignment means.

In describing the drawings, and throughout this specification and claimsexcept where another meaning is indicated, the terms inward and innerrefer to the work-table side of the shear, and outward and outer, theside away from the work-table; forward means the direction in which theshear propels itself, and also its end which faces that direction, andaft" means the opposite of forward.

The shear illustrated in these drawings consists of two principalportions, a removable shear, generally designated 1 and shown separatelyin Figures 1, 2 and 3;

2 ,708,480 Patented May 17, 1955 and a carriage, generally designated 2and shown separately in Figure 4.

In Figure 4, the carriage is shown mounted on an elongated horizontalrectilinear track, designated a, secured by brackets such as the bracketb to the side of 'a work table generally designated 0 having an upper 6which extend spacedly over the top of the rectilinear track a; and whichsupport the vertical trunnions 7 inward of the track a. Beneath saidtrunnions 6 are mounted the inner rollers 8 which bear against the innerside of the upper margins of the rectilinear track a.

Near the lower portion of the rectilinear track a, the carriage plate 5has a roller aperture 9 (see Figure 5), outward of which is the lowerend of a vertical roller pin 10, which pin is welded to the outer sideof the car: riage plate 5 above the aperture 9. The vertical roller pin10 supports an outer roller 11 protruding through the roller aperture 9,as shown in Figure 4, to bear against the outer surface of therectilinear track a near its lower edge.

On the inner side of the carriage plate 5 near its lower edge is awelded abutment strip 12. Referring to Figures 4, 5 and 6, it isapparent that the top rollers 3, the inner rollers 8, the outer roller11 and the abutment strip 12 permit the carriage 2 to ride along therectilinear track a and be held thereon securely by the weight of theremovable shear 1.

At the forward end of the carriage 2 are protruding upper and lower leadportions 13, 13', each having a substantially horizontal upper bearingface 14, 14, respectively, and each further having welded to the outerside thereof the vertical aligned upper and lower caster pins 15, 15'.

The removable shear 1 is mounted to the carriage 2 and supported thereonby upper and lower caster lugs 16, 16' having aligned lug bores 17 onthe caster axis designated e, as shown in Figures 1, 2, 3 and 5. Thelower faces of the caster lugs 16, 16 bear upon and against the upperbearing faces 14 and 14' and permit the shear 1 to swing in a horizontalplane about the caster axis e. The upper and lower caster lugs 16, 16are welded to the forward end of a shear frame outer plate 18, which isthe principal structural member of the removable shear 1. The shear 1will now be described in detail.

The shear frame outer plate 18 is located outward of the caster axis e,as shown in Figure 7. Its upper edge is referred to hereafter as thesloping scrap deflector edge 19, as shown in Figure 1, which commencesbelow the plane of work d, established by the work table 0 of Figure 4and extends aft and upward. On its inner side, above the plane of workd, and adjacent its aft end, is mounted a cross-over insert portion 20,which sup ports an upper inner plate 21 inward of the lug bores 17,having at its top an upward-extending handle 22.

Cutters of the shear 1 are arranged as follows: An idling disc cutter 23is supported on an upper lateral cutter axis 24 so that it is on theouter side of the upper inner plate 21, its cutting edge beingoutermost. A driven disc cutter 25 is supported beneath and slightly aftof the upper lateral cutter axis 24, on a lower lateral shaft 26, and onthe inner side of the shear frame outer plate 18, so that the idlingcutter 23 and driven cutter 25 are held spaced in cutting relationshipadjacent each other,

as shown in Figures 3 and 5. Inasmuch as the crossover insert portion 20is inserted between the upper inner plate 21 and the shear frame outerplate 13 at the rear portions thereof, the idling disc cutter 23 and thedriven disc cutter 25 operate in a cutter opening designated 27 in whichsheet metal may be inserted. The driven cutter 25 has a knurledperipheral portion 28, as shown in Figures 2 and 6. This knurled edgeportion 28 engages the lower surface of metal sheets inserted in thecutter opening 27 as the cutter 25 rotates under power supplied by themotor 34. The engagement of the knurled edge portion 28 adds to thetractive effort exerted by the driven cutter 25. This effort is referredto as the tractive force, and it pulls the shear 1 and carriage 2horizontally along the rectilinear track 1: under propulsive powertransmitted as hereinafter described.

The driven disc cutter 25 is secured adiaccnt the inner end of the lowerlateral shaft 26 penetrating the shear frame outer plate 18. The portionof the shaft 26 projecting inward beyond the cutter 25 is accommodatedin an adjacent clearing hole 29 in the carriage plate 5, shown in Figure5.

To the outer end of the shaft 26 is secured a pinion gear 30, driven bya worm gear 31 mounted on the forward end of a longitudinal shaft 32which is supported by a sleeve 33 welded to the outer side of the shearframe outer plate 18. Power is supplied to the longitudinal shaft 32from an electric motor 34 mounted parallel to the shaft 32, throughsheaves 3S and a V-belt 36. The motor 34 is mounted by a U-bracket 37 toa horizontal frame plate 38 welded to the lower edge of the shear frameouter plate 18 beneath the sleeve 33. A gear guard box 39 is welded tothe shear frame outer plate 18 and the horizontal frame plate 38, givingit further support.

As described to this point, the removable shear 1 may be mounted ontothe carriage 2 by slipping its upper and lower caster lugs 16, 16' overand onto the upper and lower caster pins 15, 15 of the carriage 2. As somounted, the removable shear 1 would be free to swing in a horizontalplane about the vertical caster axis 6, until lateral contact was madebetween the inner side of the driven cutter 25 and the outer side of thecarriage plate 5. The alignment of the parts is shown in Figure 7, whichis a section taken along line 77 of Figure 5.

in order to establish an initial position, an adjustment screw 49 isinserted through a cleared hole 41 in the carriage plate and supportedin position in a tapped hole 42 in the shear frame outer plate 18. Aspacer 43, which may be tubular as shown in Figure 7, is mounted on theshaft of the screw 40 and inserted between the shear frame outer plate18 and the carriage plate 5. Its width establishes the initial angularposition shown in Figure 7; and a compression spring 44, similarlymounted on the shaft of the screw 40 but which operates between the headof the adjustment screw 40 and the carriage plate 5, tends to restorethis position when disturbed. It is noted that this initial positionheads the shear 1 slightly outward of parallelism with the track a. Theamount of outward heading is usually of the order of 2, but may bereadily established under particular conditions by trying out spacers,such as the spacer 43, of varying thicknesses.

As soon as the shear 1 tractively engages and begins to propel itselfacross the metal sheet being cut, the castering'tendency of the machinemanifests itself. It can progress only in the direction which thecarriage moves the caster pins 15, Therefore its tractive force causesit to caster, or tend to swing into line behind the caster pins 15, 15.Hence the cutters 23, tend to follow a line parallel to the rectilineartrack a. The bearing of the inner face of the driven cutter 25 againstthe outer sheared edge of the sheet just aft of the point of cut tendsto assure continued linearity of the cut edge with the forward movementof the castering axis e.

irregularities in the metal sheet, for example, in its grain structure,may cause a slight temporary angular deviation of the shear 1 from truealignment with the rectilinear track a. The machines castering tendency,subject to the resiliency of the spring 44, as modified by adjusting itstension by the screw 40, tends to restore the cutters 23, 25 to properalignment as soon as the irregularity has been passed.

As a cut is started, the spring 44 substantially minimizes the possibleinitial angular deviation from the intended line of cut. After a 'cuthas been started, the spring 44 is of less importance. The fact that theshear 1 is self-aligning substantially eliminates the tendency ofoutside forces to divert it from a true line of cut. Accordingly, thereresults a out which follows the line of the rectilinear track a withouteither pulling the sheet metal from the table or pushing it farther ontothe table. irregularities in line of cut arising from the casteringfreedom of the shear 1 are too slight to be noticeable in the finishedproduct, although its freedom'to accommodate itself to irregularities isapparent when the mechanism is viewed while operating.

A factor which favors the accuracy of the present shear is the staggerof the axis 24 of the idling cutter 23 forward of that of the lateralshaft 26. This stagger presents a larger portion of the inner face ofthe driven cutter 25 against the cut edge of the sheet, which stabilizesthe movement of the shear.

An alternative arrangement for aligning the carriage 2 and the shear 1resiliently with respect to each other is shown in Figure 8. Instead ofa spacer 43 and spring 44, as shown in Figure 7, there is utilized inthe embodiment shown in Figure 8 a pair of opposed compression springs45. These are mounted on the shaft of the screw 49 on opposite sides ofand bearing against the carriage plate 5, and urge the said shear frameouter plate 18 and the carriage plate 5 resiliently in parallelalignment. In this arrangement the shear 1 is likewise free toaccommodate by angular movement for any irregularities which might beencountered in the sheet. Thus, rcctilinearity of cut is preserved in amanner much similar to that which has been heretofore described.

The idling cutter 23 is preferably mounted within the inner plate 21 inan eccentric spacing insert 46, so that slight adjustments in overlap ofthe cutters 23, 25 may be made to accommodate sheets of varyingthicknesses.

Other modifications in structural details, to adapt the presentinvention to varying uses will be apparent to those skilled in the art.Accordingly, the present invention is not to be construed narrowly butcoextensive with the inventive principles herein disclosed.

I claim:

I. A shear adapted to be propelled along a fixed horizontal path,comprising a carriage moveable along such path, a cutter-bearing frameborne by the carriage and adapted to travel normally in parallelalignment therewith, and cutter means on the frame having a shearingedge disposed in a vertical plane and positioned to cut in the directionof forward carriage movement, together with vertical pivot meansconnecting the carriage to the frame in advance of the cutter means, thepivot means moving with the carriage along such path and permitting theframe limited angular movement in a horizontal plane into and out of itsnormal parallel alignment with the carriage, whereby forward movement ofthe carriage tends to caster the frame into such parallel alignment, thecutter means including a rotatable cutter mounted on a lateral shaft,together with motor means and power-transmission means engaging themotor means to drive the rotatable cutter so as to tractively engage andprogressively shear a sheet of material against which the retatablecutter is brought and thereby move the carriage progressively forwardalong such path.

2. A self-propelled shear for sheet material adapted for cutting duringforward movement along a rectilinear track extending in a horizontalpath, comprising a vertical carriage plate having means supporting it onand in parallel alignment alongside such track and having vertical pivotmeans at its forward portion, further comprising a shear frame mountedto the carriage plate by the pivot means and thereby permitted limitedangular movement in a horizontal plane behind the pivot means into andout of parallelism with the carriage plate, a shearing cutter mounted tothe shear frame and adapted to shear in a vertical plane and in thedirection of forward movement, the shearing cutter having cutter meansincluding a rotatable cutter on a lateral shaft mounted to the frame aftof the pivot means, a motor, and power-transmitting means engaging themotor to drive the rotatable cutter whereby the said cutter wi l exert atractive force against a sheet of such sheet material as may be placedin engagement thereagainst, the tractive force being reacted against thepivot so as to advance the frame along such rectilinear track.

3. A self-propelled sheet metal shear as defined in claim 2, the cutterso driven being disc-like and having a knurled edge for tractivelyengaging such sheet of metal to be sheared thereby.

A self-propelled sheet metal shear as defined in claim 2, the cuttermeans including a rotatable, idling disc cutter mounted to the frame ona shaft above the level of and inwardly adjacent the line of cut, themotordriven cutter being mounted to the frame on a shaft below the levelof and outwardly adjacent the line of cut.

5. A self-propelled sheet metal shear as defined in claim 2, the saidmotor-driven cutter being mounted to the frame below the level of andoutwardly adjacent the line of cut, the frame having a scrap-deflectingportion sloping upward aft of the said motor-driven cutter to a pointabove said line of cut, further having an upper frame portion extendingforward therefrom, above the level of the line of cut and on the innerside thereof, the cutter means including a cutter element mounted tosaid upper frame portion and positioned to cooperate with the saidmotor-driven cutter to sever the sheet progressively and drive thatportion of the severed sheet outward of the line of cut, up and over thescrapdeflecting portion of the frame.

6. A self-propelled sheet metal shear as defined in claim 2, the saidmotor-driven cutter being mounted to the frame on a first cross-shaftbelow the level of and outwardly adjacent the line of cut, the framehaving a scrap-deflecting portion sloping upward aft of said motordrivcncutter to a point above the line of cut, further having an upper frameportion extending forward therefrom above the level of the line of cutand on the inner side thereof, the cutter means including an upperidling disc cutter mounted for rotation onto a second cross-shaft in theupper frame portion above the level of and forward of said firstcross-shaft.

7. A self-propelled sheet metal shear as defined in claim 2, togetherwith a pivot stop, and spring means yieldingly urging the frame aft ofthe pivot toward the carriage a predetermined angular amount beyondcentered position against said pivot stop, subject to the tendency ofthe shear to center behind the pivot means under the propulsive tractionof the cutter so driven by the motor.

8. A self-propelled sheet metal shear as defined in claim 2, togetherwith balanced spring means engaging the carriage and frame aft of thepivot means and urging the frame pivotally to a position of angularalignment wherein the line of cut is substantially parallel to the pathalong which the carriage is moveable.

9. A self-propelled sheet metal shear as defined in claim 2, togetherwith a rectilinear track for the carriage adapted for secure mountingalong and below the edge of a Work table at such level as to transportthe cutter means in cutting relationship at substantially the level ofsuch work table.

10. A self-propelled shear for sheet material adapted for cutting duringforward movement along a rectilinear track extending in a horizontalpath, comprising a vertical carriage plate having roll means supportingit on and in parallel alignment alongside such track and having verticalpivot means at its forward portion, further comprising a shear framemounted to the carriage plate by the pivot means and thereby permittedlimited angular movement in a horizontal plane behind the pivot meansinto and out of parallelism with the carriage plate, a shearing cuttermounted to the shear frame and adapted to shear in a vertical plane inthe direction of forward movement, the shearing cutter having cuttermeans including a rotatable cutter on a lateral shaft mounted to theframe aft of the pivot means, a motor, and powertransmitting meansengaging the motor to drive the rotatable cutter whereby the said cutterwill exert a tractive force against a sheet of such sheet material asmay be placed in engagement thereagainst, the tractive force beingreacted against the pivot so as to advance the frame along suchrectilinear track, the shear frame fur ther having a fixed alignmentportion positioned alongside and spaced from the side of the carriageplate opposite such track, and resilient restraint means displaced fromthe pivot means and yieldingly urging the alignment portion of the shearframe toward parallelism with the carriage plate.

11. A self-propelled. shear for planar material, the shear being adaptedfor cutting during forward movement along a rectilinear track extendingin a path parallel to the plane in which such material is to be placedfor shearing, comprising a planar work surface, a rectilinear trackmounted parallel to the plane thereof, a carriage having meanssupporting it on such track and having pivot means perpendicular to theplane of the work surface at the forward portion of the carriage, ashear frame borne by the carriage and connected to it by the pivot meansand thereby permitted limited angular movement in a plane parallel tothe work surface plane behind the pivot means into and out ofparallelism with the track, a shearing cutter mounted to the shear frameand adapted to shear in a plane perpendicular to the work surface and inthe direction of forward movement, the shearing cutter having cuttermeans including a rotatable edged cutter aft of the pivot means on alateral shaft mounted to the frame, a motor, and power-transmittingmeans engaging the motor to drive the rotatable cutter, whereby the saidcutter will progressively shear into and exert tractive force on a sheetof planar material placed against the work surface and which the cuttermay engage, the tractive force being reacted against the pivot so as toadvance the frame along said rectilinear track.

References Cited in the file of this patent UNITED STATES PATENTS609,213 Ridgeley Aug. 16, 1878 733,511 Ridgeley July 14, 1903 1,154,924Holub Sept. 28, 1915 1,241,313 Wagner Sept. 25, 1917 2,060,600 WeissNov. 10, 1936 2,216,108 Brockway Oct. 1, 1940

